1. Field of the invention
The present invention is related to a three-dimensional simple flexible mould for bending pipes. When a pipe-bending machine is used to execute a three-dimensional pipe-bending (or bending forming) process on a metallic pipe, the flexible mould suits those metallic pipes with smaller flexibility and stiffness as well as with smaller diameters and thin walls. The flexible mould can effectively scatter the stress on a pipe wall during bending process, and therefore deformation of the pipe wall due to stress concentration can be prevented. The flexible mould can also be removed from a bent pipe conveniently after the three-dimensional bending forming process. Therefore, convenience of operation of the three-dimensional bending forming process can be ensured.
2. Description of the Prior Art
In the known pipe-bending processing techniques, pipe-bending machines are used to directly bend and rectify metallic pipes with larger stiffness. However, up to the present day, it is not that all metallic pipes are suitable for bending forming process. In fact, during bending forming, a pipe must have a certain thickness and stiffness in order to keep the capability of preventing from deformation.
The pipes are not suitable to be processed by bending forming directly with a pipe bending machine in the conventional techniques. This is because the material of which the metallic pipes are made has smaller stiffness than steel alloy. Therefore when in bending forming, the pipe wall is subjected to overly large concentration of stress, and the pipe wall is subjected to collapse.
And more, it is not that all steel alloy pipes are suitable for bending forming processes. In fact, a metallic pipe, no matter what material it is made of, will be more difficult to deal with in a bending forming process when its diameter is very small and its pipe wall is thinner. This is a technical impediment making difficulty of the bending forming process.
Based on the above stated reasons, mass production of three-dimensional metallic pipes in the industry has been being hard to put to practice by a simple way.